Yadda ake Amfani da Dokokin cat da Tac tare da Misalai a cikin Linux
Wannan labarin wani ɓangare ne na jerin Dabaru da Tukwici na Linux ɗinmu, a cikin wannan labarin za mu rufe wasu mahimman amfani da umarnin cat (mafi yawan umarnin da ake amfani da shi a cikin Linux) da tac (juyayin umarnin cat - buga fayiloli a cikin tsari) tare da wasu masu amfani. misalai.
Asalin Amfani da Dokar Cat a cikin Linux
Umurnin Cat, gajarta na Concatenate, shine ɗayan umarnin da aka fi amfani dashi a cikin tsarin nix. Mafi mahimmancin amfani da umarnin shine karanta fayiloli da nuna su zuwa stdout, ma'ana nuna abun ciki na fayiloli akan tashar ku.
# cat file.txt
Wani amfani da umarnin cat shine karanta ko haɗa fayiloli da yawa tare da aika fitarwa zuwa mai saka idanu kamar yadda aka kwatanta a cikin misalan da ke ƙasa.
# cat file1.txt file2.txt file3.txt
Hakanan za'a iya amfani da umarnin don haɗa (haɗe) fayiloli da yawa cikin fayil ɗaya ta amfani da \>” afaretan turawa Linux.
# cat file1.txt file2.txt file3.txt > file-all.txt
Ta amfani da append redirector za ka iya ƙara abun ciki na sabon fayil zuwa kasan file-all.txt tare da haɗin gwiwar mai zuwa.
# cat file4.txt >> file-all.txt
Ana iya amfani da umarnin cat don kwafi abun ciki na fayil zuwa sabon fayil. Za a iya canza sunan sabon fayil ɗin ba bisa ka'ida ba. Misali, kwafi fayil ɗin daga wurin da ake yanzu zuwa /tmp/ directory.
# cat file1.txt > /tmp/file1.txt
Kwafi fayil ɗin daga wurin da ake yanzu zuwa /tmp/ directory kuma canza sunansa.
# cat file1.txt > /tmp/newfile.cfg
Ƙarƙashin amfani da umarnin cat shine ƙirƙirar sabon fayil tare da haɗin gwiwar da ke ƙasa. Lokacin da aka gama gyara fayil ɗin danna CTRL+D don adanawa da fita sabon fayil ɗin.
# cat > new_file.txt
Domin ƙididdige duk layukan fitarwa na fayil, gami da layukan wofi, yi amfani da maɓallin -n.
# cat -n file-all.txt
Don nuna kawai lambar kowane layi mara amfani yi amfani da maɓallin -b.
# cat -b file-all.txt
Kuna son ƙarin koyo game da umarnin cat na Linux? sannan karanta labarinmu game da Misalan Umurnin 'cat' 13 masu amfani a cikin Linux.
Koyi Yadda ake Amfani da Tac Command a Linux
A gefe guda, umarnin da ba a san shi ba kuma ba a yi amfani da shi ba a cikin * tsarin nix shine umarnin tac. Tac kusan shine juzu'in umarnin cat (kuma an rubuta shi baya) wanda ke buga kowane layi na fayil wanda ya fara daga layin ƙasa kuma yana ƙarewa a saman layi zuwa daidaitaccen kayan aikin injin ku.
# tac file-all.txt
Ɗaya daga cikin mafi mahimmancin zaɓi na umarni yana wakilta ta hanyar canjin -s, wanda ke raba abubuwan da ke cikin fayil ɗin bisa la'akari da kirtani ko kalma daga fayil ɗin.
# tac file-all.txt --separator "two"
Bayan haka, mafi mahimmancin amfani da umarnin tac shine, cewa zai iya ba da taimako mai girma don gyara fayilolin log, yana mai da tsarin tarihin abubuwan da ke cikin log ɗin.
$ tac /var/log/auth.log Or to display the last lines $ tail /var/log/auth.log | tac
[email ~ $ tac /var/log/auth.log pr 6 16:09:01 tecmint CRON[17714]: pam_unix(cron:session): session closed for user root Apr 6 16:09:01 tecmint CRON[17714]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 16:05:01 tecmint CRON[17582]: pam_unix(cron:session): session closed for user root Apr 6 16:05:01 tecmint CRON[17583]: pam_unix(cron:session): session closed for user root Apr 6 16:05:01 tecmint CRON[17583]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 16:05:01 tecmint CRON[17582]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 16:00:01 tecmint CRON[17434]: pam_unix(cron:session): session closed for user root ....
[email ~ $ tail /var/log/auth.log | tac Apr 6 16:09:01 tecmint CRON[17714]: pam_unix(cron:session): session closed for user root Apr 6 16:09:01 tecmint CRON[17714]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 16:05:01 tecmint CRON[17582]: pam_unix(cron:session): session closed for user root Apr 6 16:05:01 tecmint CRON[17583]: pam_unix(cron:session): session closed for user root Apr 6 16:05:01 tecmint CRON[17583]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 16:05:01 tecmint CRON[17582]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 16:00:01 tecmint CRON[17434]: pam_unix(cron:session): session closed for user root Apr 6 16:00:01 tecmint CRON[17434]: pam_unix(cron:session): session opened for user root by (uid=0) Apr 6 15:55:02 tecmint CRON[17194]: pam_unix(cron:session): session closed for user root Apr 6 15:55:01 tecmint CRON[17195]: pam_unix(cron:session): session closed for user root ...
Daidai da umarnin cat, tac yana yin kyakkyawan aiki wajen sarrafa fayilolin rubutu, amma yakamata a guji shi a cikin wasu nau'ikan fayiloli, musamman fayilolin binary ko akan fayiloli inda layin farko. yana nuna shirin da zai gudanar da shi.